Protecting piling from teredos and the like



April 8, 1924. 1,489,798

- c. P. TATRO ET AL PROTECTING FILING FROM TEREDOS AND THE LIKE Original Filed March 21. 1921 INVENTORS OREYS Patented Apr. S, Ed e UNTTEE STATES CHARLES P. TA'IRO AND GEORGE DEIJIUS, OF SEATTLE, WASHINGTON.

PROTECTING FILING FROM TEREDOS AND THE LIKE.

Application filed March 21, 1921, Serial Ito. 45%,165. Renewed September 26, 1923.

To all whom it may concern:

Be it known that we, CHARLES P. TA'rRo and GEORGE DELIUS, citizens of the United States of America, and residents of the city of Seattle, in the county of King and State of Washington, have invented certain new and useful Improvements in Protecting Piling from Teredos and the like, of which the following is a specification.

Our invention relates to a process for protecting wooden piling from the attacks of teredo and other wood borers. The present application is an improvement upon our Patent No. 948,355.-

The object of our present invention is to produce a process for the purpose described which is more eficient, particularly in chlorine generation, than that of our previous patent, and to produce a process by the use of which a large part of the rather cumbersome and expensive apparatus is eliminated.

Our invention comprises those novelsteps which are described in the following specification and particularly defined by the claims terminating the same, one form of apparatus for carrying out the process being shown in the accompanying drawings.

The drawings illustrate a series of piles supporting a wharf, and a form of apparatus-in connection therewith which may be used in carrying out our rocess.

In our patent referred to a ove, two electrolytic terminals, a cathode and an anode, are placed adjacent a pile to be protected, and current is then passed through the circuit, the sea-water forming the electrolyte. In this connection it should be noted that the teredo is one of a series of salt water molluscs and does not exist in fresh water. Thus, whenever it is desired to use our process for protecting wooden piling or other structure against teredo, it is always possible to utilize the water in which the piles stand as an electrolyte.

Our former apparatus, while efiective, was not as eficient as it might have been. The cathode and anode were both submerged adjacent each other and adjacent the pile to be protected. This required a double series of electric leads, positive and negative, for each pile to be protected. Further, as sea-water is decomposed by electrolysis, chlorine is liberated at the anode and sodium hydroxide and hydrogen are formed at the cathode. The hydroxide and chlorine, having a strong aflinit-y one for the other, will, when in such close proxlmlty, react one upon the other with the result that a large portion of the chlorine is lost in the formation of hypochlorites, which were of little value in protecting the piling against teredo.

Sea-water is of relatively high conductivity, and its resistance is so slight as to be measured only with the most delicate instruments. It is possible, therefore, to pass a relatively weak current through sea-water to a great distance. This fact we utilize in our improved process, placingthe cathode at a distance from the anode. Preferably we employ a single cathode and a large number of anodes. Thus one anode may be placed adjacent each pile to be protected and the single cathode, being placed at a distance, serves for the entire series of anodes.

By the arrangement described, the chlorine which is liberated at the anodes is removed from the sodium hydroxide formed at the cathode. This obviates the formation of hypochlorites and assures the maximum efficiency from the chlorine generated. N0 chlorine is lost by this method except such as may be absorbed or dissolved in the water immediately surrounding it. This chlorine water, however, comes in contact with the piles and is as efiective as the chlorine in destroying teredo, especially as its tendency is to sink to the foot of the pile, on account of its specific gravity being higher than the sea-water.

The preferred arrangement of the appara-= tus which is illustrated in the drawing contemplates the wrapping about each ile of a flexible insulated conductor 1 aving thereon a plurality of terminal balls 2, which are e ectrically connected to the fiexible conductor. These are spaced at intervals upon the conductor 1, and are of material which is insoluble and non-corrosive by the chlorine liberated. Carbon in the form of graphite is a suitable material for such balls. The flexible conductor, carryin the balls, may be wrapped about the pi e 3 as many times as desired and the coils so formed may be closer or farther apart as the circumstances may require. The cathode 5 is placed at a distance from any of the anodes, as explained above, and

may be, as shown here, a sheet 0t conductno ing material, such as iron. Other arrangements and apparatus may be found des rable to suit varying conditions.

As current is turned on in the circuit, chlorine is liberated from each of the balls 2. These are in intimate contact 'withthe pile 3 and the chlorine generated is brought into contact with the pile. The gaseous chlorine rises along the pile and the chlorine water sinks. Thus the pile is swept upward and downward with nascent chlorine. The teredo always lies in his bore with two feelers and feed tubes exposed and reaching into the water for sustenance. l/Vhen the nascent chlorine or chlorine water comes in contact with these feelers and feed tubes,

the teredo is destroyed thereby. The effect is in no sense electrical, but is rather due to the destructive effect of the chlorine.

In this process the current employed should always be direct current and the direction thereof should never be reversed, nor should the cathode be brought close to any one of the anodes, for it is our desire to generate only chlorine at the anodes. Any generation of a hydroxide at or near the anodes, such as would occur if the current were reversed, or if the electrodes were close to each other, would neutralize the chlorine generated, and so render the process less effective, as was the case in our former rocess, where the two terminals were ad acent one to the other.

We refer to employ metallic cathode. Now, ii the current were reversed, the carbon anodes would become the cathodes generating hydrogen and sodium hydroxide,

g and the metal cathode would become the anode. No chlorine would then be formed, butrather the chloride of the metal which composed the new anode. This would have no efiect in destroying the teredo or other borers.

What we claim as our invention is:

1. The process of protecting wooden pilmenace be protected, in placing a cathode in the water at a distant point, and in passing a direct current through these terminals, the water forming the electrolyte.

3. The process of protecting wooden piling in salt water from'teredo and the like which consists in placing an anode in the water in intimate juxtaposition to the pile, in placing a cathode in the water at a distant point, and in passing a direct current through these terminals, the circuit being completed through the water.

4. The process of protecting wooden .piling in salt water from teredo and the like, which consists in wrapping an elongated, substantially continuous insoluble anode about the pile, in placing, a cathode in the water at a distant point, and in passing a direct current through said terminals, the circuit being completed through the water.

5. The process of protecting a series of spaced wooden piles in salt water from teredo and the like, which consists in placing'an anode in the water adjacent each pile, in placing a single common cathode in the water at a distant point, and in passing a direct current through said terminals, the water formin the electrolyte.

Signed at Seattle, Kin County,"Washington, this lfith day of arch, 1921.

CHARLES P. TATRO. enoncn DELIUS. 

